Immunostaining of cytoskeletal and junctional proteins in cultured human arachnoid granulation epithelial cells. A. Expression of intermediate filament protein vimentin (Cy3 conjugated anti-vimentin antibody). B. Expression of cytokeratin (FITC conjugate to broad spectrum anti-cytokeratin antibody). C. Expression of connexin43 (FITC conjugate); punctate distribution at borders (red arrows) points to gap junctions in cell culture. D. ZO-1 (tight junction) staining (FITC conjugate) at cell-cell borders (white arrow) demarcates overlapping filapodia (short linear structures in parallel). E. Expression of desmoplakin (with Alexa Fluor 555 conjugated secondary antibody) reveals desmosomes along adjacent cell borders (white arrows). F. Expression of E-cadherin, an epithelial-specific cell adhesion molecule, at periphery of cells (white arrows) in a pattern similar to that of connexin43 and ZO-1. All images have same scale (bar = 50 μm). Reproduced with permission of Holman et al .